Fungi

FUNGI?

Fungi is a kingdom of unicelluar and multicellar heterotrophic organisms.

Fungi digest food outside their bodies: they release enzymes into the surrounding environment, breaking down organic matter into a form the fungus can absorb. Mycorrhizal associates benefit from this by absorbing materials digested by the fungi growing among their roots.

Fungi reproduce by releasing spores from a fruiting body. The fruit, called a mushroom, releases spores into the air, and the wind carries the spores off to start the next generation. Around 100,000 species of fungi are divided into five phyla, based largely on the characteristics of their reproductive organs.

PHYLUMS

ZYGOMYCOTA phylum contains the thick-walled sexual structures called zygosporangia. This fungi group consist of many organisms who live in the soil and feed on decaying plant and animal matter. Asexual reproduction occurs most often, where haploid spores are produced in specialized hyphae that end with spore-producing structures called sporangia.
During Sexual reproduction, two hyphae from opposite mating strains fuse. Complete septa form hehind the tips of the touching hyphae forming a chamber containing numerous haploid nuclei. Then the haploid nuclei fuse to form diploid nuclei. The newly developed structure contains a number of zygotes and is protected in a tough dormant zygosporangium. The zygotes in the zygosproangium undergo meiosis when conditions become favorable again and the zygosporangium germinates producing sporangia. Haploid spores develop within the sporangia and are scattered by air when the sporangia ruputures.

ASCOMYCOTA phylum contains ascus, which are club-shaped, saclike structures in which haploid spores are formed. Asci usually form within the tightly interwoven hyphae of a complex structure called an ascocarp.
There are many different types of Ascomycetes that have played a significant role on our planet among them are the following.
1) Endothia parasitica- around 1890 brought the disease called chestnut blight and destroyed virtually all the chestnut trees within a few years.
2) Ceratocystis ulmi- brought on the dutch elm disease
3) Very useful yeast also belong to this phylum. Although there are some yeast like Candida which are human pathogens. Candida is a common source of thrush.
4) The flavorful morels and truffles also are found in this phylum.
Sexual and Asexual reprodruction of the Ascomycota group is very similar to the zygomycota group. The main difference is that the specialized spores which are produced are called Conidia.

BASIDIOMYCOTA is the 3rd phyla of fungi which show sexual reproduction. These fungi are probably more familiar to everyday people. Most of the mushrooms we know of are found within this group. The mushrooms, toadstools, puffballs, jelly fungi, and shelf fungi make up this group. These organisms are named for their club-shaped sexual repriductive structure called the basidium. Here asexual reproduction is rare.
Under proper conditions, underground hyphae grow upward and weave together to produce a mushroom, the reproductive structure of fungi. This structure consist of a stalk and cap. The underside of the cap is lined with thousands of club-shaped reproductive cells called basidia. Through a series of fusion and meiosis each basidium produces spores, that are released and germinate into new hyphae.

Species

One species that is in the Fungi Kingdom is Agaricus pocillator. It's genus name is agraicus. This woodland mushroom is distributed through southeastern North America, and ranges at least as far north as Illinois. It can be distinguished in the field by its (usually) dark center, its relatively slight stature, and its small, bulbous base, which stains yellow, inside and out. It can be found under deciduous trees and in mixed woods during the summer and fall.